/*
  SelectTaskDialog.cpp

  This file is part of Charm, a task-based time tracking application.

  Copyright (C) 2014-2018 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com

  Author: Frank Osterfeld <frank.osterfeld@kdab.com>

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 2 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "SelectTaskDialog.h"
#include "ExpandStatesHelper.h"
#include "GUIState.h"
#include "ViewHelpers.h"

#include <QPushButton>
#include <QSettings>

#include "ui_SelectTaskDialog.h"

SelectTaskDialogProxy::SelectTaskDialogProxy(CharmDataModel *model, QObject *parent)
    : ViewFilter(model, parent)
{
    // we filter for the task name column
    setFilterKeyColumn(Column_TaskId);
    setFilterCaseSensitivity(Qt::CaseInsensitive);
    setFilterRole(TasksViewRole_Filter);
    prefilteringModeChanged();
}

bool SelectTaskDialogProxy::filterAcceptsColumn(int column, const QModelIndex &) const
{
    return column == Column_TaskId;
}

Qt::ItemFlags SelectTaskDialogProxy::flags(const QModelIndex &index) const
{
    if (index.isValid()) {
        return Qt::ItemIsEnabled | Qt::ItemIsSelectable;
    } else {
        return Qt::NoItemFlags;
    }
}

QVariant SelectTaskDialogProxy::data(const QModelIndex &index, int role) const
{
    if (index.isValid() && role == Qt::CheckStateRole) {
        return QVariant();
    } else {
        return ViewFilter::data(index, role);
    }
}

SelectTaskDialog::SelectTaskDialog(QWidget *parent)
    : QDialog(parent)
    , m_ui(new Ui::SelectTaskDialog())
    , m_proxy(MODEL.charmDataModel())
{
    m_ui->setupUi(this);
    m_ui->treeView->setModel(&m_proxy);
    m_ui->treeView->header()->hide();
    m_ui->buttonBox->button(QDialogButtonBox::Cancel)->setEnabled(true);
    m_ui->buttonBox->button(QDialogButtonBox::Ok)->setEnabled(false);
    connect(m_ui->treeView->selectionModel(), &QItemSelectionModel::currentChanged,
            this, &SelectTaskDialog::slotCurrentItemChanged);
    connect(m_ui->treeView, &QTreeView::doubleClicked,
            this, &SelectTaskDialog::slotDoubleClicked);

    connect(m_ui->filter, &QLineEdit::textChanged,
            this, &SelectTaskDialog::slotFilterTextChanged);
    connect(m_ui->showExpired, &QCheckBox::toggled,
            this, &SelectTaskDialog::slotPrefilteringChanged);
    connect(m_ui->showSelected, &QCheckBox::toggled,
            this, &SelectTaskDialog::slotPrefilteringChanged);
    connect(this, &SelectTaskDialog::accepted,
            this, &SelectTaskDialog::slotAccepted);
    connect(MODEL.charmDataModel(), &CharmDataModel::resetGUIState,
            this, &SelectTaskDialog::slotResetState);
    connect(m_ui->filter, &QLineEdit::textChanged,
            this, &SelectTaskDialog::slotSelectTask);

    QSettings settings;
    settings.beginGroup(QString::fromUtf8(staticMetaObject.className()));
    if (settings.contains(MetaKey_MainWindowGeometry))
        resize(settings.value(MetaKey_MainWindowGeometry).toSize());
    // initialize prefiltering
    slotPrefilteringChanged();
    m_ui->filter->setFocus();
}

SelectTaskDialog::~SelectTaskDialog()
{
}

void SelectTaskDialog::slotResetState()
{
    QSettings settings;
    settings.beginGroup(QString::fromUtf8(staticMetaObject.className()));
    GUIState state;
    state.loadFrom(settings);
    QModelIndex index(m_proxy.indexForTaskId(state.selectedTask()));
    if (index.isValid())
        m_ui->treeView->setCurrentIndex(index);

    Q_FOREACH (const TaskId id, state.expandedTasks()) {
        QModelIndex indexForId(m_proxy.indexForTaskId(id));
        if (indexForId.isValid())
            m_ui->treeView->expand(indexForId);
    }

    m_ui->showExpired->setChecked(state.showExpired());
    m_ui->showSelected->setChecked(state.showCurrents());
}

void SelectTaskDialog::showEvent(QShowEvent *event)
{
    slotResetState();
    QDialog::showEvent(event);
}

void SelectTaskDialog::hideEvent(QHideEvent *event)
{
    QSettings settings;
    settings.beginGroup(QString::fromUtf8(staticMetaObject.className()));
    settings.setValue(MetaKey_MainWindowGeometry, size());
    QDialog::hideEvent(event);
}

TaskId SelectTaskDialog::selectedTask() const
{
    return m_selectedTask;
}

void SelectTaskDialog::selectTask(TaskId task)
{
    m_selectedTask = task;
    QModelIndex index(m_proxy.indexForTaskId(m_selectedTask));
    if (index.isValid())
        m_ui->treeView->setCurrentIndex(index);
    else
        m_ui->treeView->setCurrentIndex(QModelIndex());
}

void SelectTaskDialog::slotCurrentItemChanged(const QModelIndex &first, const QModelIndex &)
{
    const Task task = m_proxy.taskForIndex(first);
    if (isValidAndTrackable(first)) {
        m_selectedTask = task.id();
        m_ui->taskStatusLB->clear();
    } else {
        m_selectedTask = 0;
        const bool expired = !task.isCurrentlyValid();
        const bool trackable = task.trackable();
        const bool notTrackableAndExpired = (!trackable && expired);
        const QString expirationDate = QLocale::system().toString(
            task.validUntil(), QLocale::ShortFormat);
        const QString info = notTrackableAndExpired ? tr(
            "The selected task is not trackable and expired since %1").arg(expirationDate)
                             : expired ? tr("The selected task is expired since %1").arg(
            expirationDate)
                             : tr("The selected task is not trackable");
        m_ui->taskStatusLB->setText(info);
    }

    m_ui->buttonBox->button(QDialogButtonBox::Ok)->setEnabled(m_selectedTask != 0);
}

bool SelectTaskDialog::isValidAndTrackable(const QModelIndex &index) const
{
    if (!index.isValid())
        return false;
    const Task task = m_proxy.taskForIndex(index);

    const bool taskValid = m_nonValidSelectable || (task.isValid() && task.isCurrentlyValid());

    if (m_nonTrackableSelectable)
        return taskValid;
    return taskValid && task.trackable();
}

void SelectTaskDialog::slotDoubleClicked(const QModelIndex &index)
{
    if (isValidAndTrackable(index))
        accept();
}

void SelectTaskDialog::slotFilterTextChanged(const QString &text)
{
    QString filtertext = text.simplified();
    filtertext.replace(QLatin1Char(' '), QLatin1Char('*'));

    Charm::saveExpandStates(m_ui->treeView, &m_expansionStates);
    m_proxy.setFilterWildcard(filtertext);
    if (!filtertext.isEmpty()) {
        m_ui->treeView->expandAll();
    } else {
        Charm::restoreExpandStates(m_ui->treeView, &m_expansionStates);
    }
}

void SelectTaskDialog::slotAccepted()
{
    QSettings settings;
    // FIXME refactor, code duplication with taskview
    // save user settings
    if (ApplicationCore::instance().state() == Connected
        || ApplicationCore::instance().state() == Disconnecting) {
        GUIState state;
        // selected task
        state.setSelectedTask(selectedTask());
        // expanded tasks
        TaskList tasks = MODEL.charmDataModel()->getAllTasks();
        TaskIdList expandedTasks;
        Q_FOREACH (const Task &task, tasks) {
            QModelIndex index(m_proxy.indexForTaskId(task.id()));
            if (m_ui->treeView->isExpanded(index))
                expandedTasks << task.id();
        }
        state.setExpandedTasks(expandedTasks);
        state.setShowExpired(m_ui->showExpired->isChecked());
        state.setShowCurrents(m_ui->showSelected->isChecked());
        settings.beginGroup(QString::fromUtf8(staticMetaObject.className()));
        state.saveTo(settings);
    }
}

void SelectTaskDialog::slotPrefilteringChanged()
{
    // find out about the selected mode:
    Configuration::TaskPrefilteringMode mode;
    const bool showCurrentOnly = !m_ui->showExpired->isChecked();
    const bool showSubscribedOnly = m_ui->showSelected->isChecked();
    if (showCurrentOnly && showSubscribedOnly) {
        mode = Configuration::TaskPrefilter_SubscribedAndCurrentOnly;
    } else if (showCurrentOnly && !showSubscribedOnly) {
        mode = Configuration::TaskPrefilter_CurrentOnly;
    } else if (!showCurrentOnly && showSubscribedOnly) {
        mode = Configuration::TaskPrefilter_SubscribedOnly;
    } else {
        mode = Configuration::TaskPrefilter_ShowAll;
    }

    CONFIGURATION.taskPrefilteringMode = mode;
    Charm::saveExpandStates(m_ui->treeView, &m_expansionStates);
    m_proxy.prefilteringModeChanged();
    Charm::restoreExpandStates(m_ui->treeView, &m_expansionStates);
    emit saveConfiguration();
}

void SelectTaskDialog::setNonTrackableSelectable()
{
    m_nonTrackableSelectable = true;
}

void SelectTaskDialog::setNonValidSelectable()
{
    m_nonValidSelectable = true;
}

void SelectTaskDialog::slotSelectTask(const QString &filter)
{
    const QString filterText = filter.simplified().toUpper().replace(QLatin1Char('*'), QLatin1Char(' '));
    const int filterTaskId = filterText.toInt();
    const TaskList tasks = MODEL.charmDataModel()->getAllTasks();

    for (const auto task : tasks) {
        if (!task.isValid())
            continue;
        if (task.name().toUpper().contains(filterText) || task.id() == filterTaskId)
            selectTask(task.id());
    }
}